When dinosaurs ruled the Earth, mammals took to the skies – Pittsburgh Post-Gazette

Pittsburgh Post-GazetteThe Mesozoic Era, from 252 million years ago to 66 million years ago, is often called the Age of Dinosaurs. To generations of paleontologists, early mammals from the period were just tiny nocturnal insect-eaters, trapped in the shadows of leviathans …BBC NewsSmithsonianNPR – – –